This paper reports architecturally designed nanocomposites synthesized by hybridizing the two-dimensional (2D) nanostructure of molybdenum disulfide (MoS 2 ) nanosheet (NS)-supported Pt nanoparticles (PtNPs) as counter electrodes (CEs) for dye-sensitized solar cells (DSSCs). MoS 2 NSs were prepared using the hydrothermal method; PtNPs were subsequently reduced on the MoS 2 NSs via the water-ethylene method to form PtNPs/MoS 2 NSs hybrids. The nanostructures and chemical states of the PtNPs/MoS 2 NSs hybrids were characterized by high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy. Detailed electrochemical characterizations by electrochemical impedance spectroscopy, cyclic voltammetry, and Tafel-polarization measurement demonstrated that the PtNPs/MoS 2 NSs exhibited excellent electrocatalytic activities, afforded a higher charge transfer rate, a decreased charge transfer resistance, and an improved exchange current density. The PtNPs/MoS 2 NSs hybrids not only provided the exposed layers of 2D MoS 2 NSs with a great deal of catalytically active sites, but also offered PtNPs anchored on the MoS 2 NSs enhanced I 3 − reduction. Accordingly, the DSSCs that incorporated PtNPs/MoS 2 NSs CE exhibited an outstanding photovoltaic conversion efficiency (PCE) of 7.52%, which was 8.7% higher than that of a device with conventional thermally-deposited platinum CE (PCE = 6.92%).

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